Blue search light cast by South Korean coast guard helicopter shows a sunken ferry in the water off the southern coast near Jindo, South Korea. / AP

by David Jackson, USA TODAY

by David Jackson, USA TODAY

President Obama offered condolences and help to South Korea on Thursday over the ferry accident that has killed an unknown number of people.

"I've directed our military to provide any and all assistance requested by our Korean partners in the days ahead," Obama said in a written statement, noting that American Navy personnel and U.S. Marines are already on the scene.

Obama, who will visit Seoul this month as part of a trip to Asia, said that "the bonds of friendship between the American and Korean people are strong and enduring, and our hearts ache to see our Korean friends going through such a terrible loss, especially the loss of so many young students."

He added: "America's commitment to our ally South Korea is unwavering - in good times and in bad. As the Korean people deal with this heartbreaking tragedy, they will have the unending support and friendship of the United States."